Organic compounds having the ability to sequester metallic ions, e.g., calcium and magnesium ions in aqueous media have many valuable applications. For example, these organic compounds may be utilized in food processing to sequester various metal ions found in the product which are detrimental to flavor, stability, etc., or they may be used in various detergent formulations to build such formulations and, therefore, increase the formulations cleaning effectiveness. This latter application is probably the largest application of such organic compounds, at least in terms of pounds consumed per year. Presently, among the most effective builders are the polyphosphates, notably sodium tripolyphosphate and tetra sodium pyrophosphate. Despite the utility of these compounds, distinct disadvantages arise from their use--most notably they are alleged to contribute significantly to the eutrophication of rivers, lakes, underground streams and other bodies of water due to the phosphorus content of the compounds. ["Detergent Phosphorus Effect on Algae" by Thomas E. Maloney, Journal of the Water Pollution Control Federation, Vol. 38, No. 1, pp. 38-45 (January 1966) ].
It is, therefore, an object of this invention to provide phosphorus-free, highly biodegradable organic compounds which do not suffer from the foregoing mentioned eutrophication problems and which, in aqueous media, are highly effective sequestrants and which, when used in detergent formulations, enhance the cleaning effectiveness thereof.
Other important objects of this invention will become apparent from the ensuing description and appended claims.